package zcw.com.lib_leet_code;

/**
 * Created by 朱城委 on 2021/9/2.<br><br>
 *
 * 中等：不同的二叉搜索树
 */
public class Topic96 {

    public static void main(String[] args) {
        Topic96 instance = new Topic96();

        System.out.println(instance.numTrees(3));
        System.out.println(instance.numTrees(1));
        System.out.println(instance.numTrees(5));
    }

    public int numTrees(int n) {
        int[] G = new int[n + 1];
        G[0] = 1;
        G[1] = 1;

        for(int i = 2; i <= n; i++) {
            for(int j = 1; j <= i; j++) {
                G[i] += G[j - 1] * G[i - j];
            }
        }

        return G[n];
    }
}
